Chamber components with polished internal apertures

ABSTRACT

Disclosed herein are systems and methods for polishing internal surfaces of apertures in semiconductor processing chamber components. A method includes providing a ceramic article having at least one aperture, the ceramic article being a component for a semiconductor processing chamber. The method further includes polishing the at least one aperture based on flowing an abrasive media through the at least one aperture of the ceramic article, the abrasive media including a polymer base and a plurality of abrasive particles.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.14/318,518, filed Jun. 27, 2014, the disclosure of which is herebyincorporated by reference herein in its entirety.

TECHNICAL FIELD

Embodiments of the present invention relate, in general, to polishinginternal surfaces of apertures in semiconductor processing chambercomponents and to chamber components with polished internal apertures.

BACKGROUND

In the semiconductor industry, devices are fabricated by a number ofmanufacturing processes producing structures of ever-decreasing size. Asthe critical dimensions for semiconductor devices continue to shrink,there is an unyielding need to improve the cleanliness of the processingenvironment within a semiconductor process chamber. Such contaminationmay be caused, in part, by chamber components. For example,contamination may be caused by gas delivery components, such as ashowerhead.

Many bulk ceramic components include small apertures that allow forprocess gas flow. These apertures are usually drilled after performing asintering process, which often results in rough internal surfacefinishes. Such rough interior surfaces serve as sources of on-waferdefects, since they are directly in contact with the flow of the processgases. To improve upon on-wafer defect performance, particulates can beat least partially removed, for example, from the rough internalapertures by thermal oxidation processes and by radio frequency (RF)conditioning of the component after thermal oxidation. However, somecomponents, such as showerheads, often involve more than 100 hours of RFconditioning prior to using in a semiconductor process chamber in orderto satisfactorily reduce particles.

SUMMARY

Embodiments of the present disclosure relate to the polishing ofinterior surfaces of apertures in ceramic articles. In one embodiment, amethod includes providing a ceramic article having at least oneaperture, the ceramic article being a component for a semiconductorprocessing chamber. The method further includes polishing the at leastone aperture based on flowing an abrasive media through the at least oneaperture of the article. The abrasive media includes a polymer base anda plurality of abrasive particles.

In another embodiment, a system includes a mounting stage, a clamp, anda pump fluidly coupled to the mounting stage by a ceramic articledisposed between the clamp and mounting stage. An abrasive media flowpath from the mounting stage to the clamp is defined by an aperture of aceramic article.

In another embodiment, a chamber component includes a ceramic body and aplurality of apertures in the ceramic body. A roughness of the pluralityof apertures is less than 32 μin.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings in which likereferences indicate similar elements. It should be noted that differentreferences to “an” or “one” embodiment in this disclosure are notnecessarily to the same embodiment, and such references mean at leastone.

FIG. 1 depicts a sectional view of a processing chamber according to anembodiment;

FIG. 2 depicts an exemplary architecture of a manufacturing systemaccording to an embodiment;

FIG. 3 depicts a sectional view of an abrasive flow system according toan embodiment;

FIGS. 4a-4i are micrographs comparing unpolished apertures to aperturespolished according to an embodiment;

FIG. 5 is a flow diagram illustrating a process for polishing interiorsurfaces of apertures in a ceramic article according to an embodimentand

FIG. 6 is a flow diagram illustrating a process 500 for polishinginterior surfaces of apertures in a ceramic article according to anembodiment according to another embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention provide a ceramic article, such asa chamber component for a processing chamber. The ceramic article mayhave a composition of one or more of Al₂O₃, AlN, SiO₂, Y₃Al₅O₁₂ (YAG),Y₄Al₂O₉ (YAM), Y₂O₃, Er₂O₃, Gd₂O₃, Gd₃Al₅O₁₂ (GAG), YF₃, Nd₂O₃,Er₄Al₂O₉, Er₃Al₅O₁₂ (EAG), ErAlO₃, Gd₄Al₂O₉, GdAlO₃, Nd₃Al₅O₁₂,Nd₄Al₂O₉, NdAlO₃, or a ceramic compound composed of Y₄Al₂O₉ and asolid-solution of Y₂O₃-ZrO₂. The ceramic article includes one or moreapertures passing through the ceramic article (e.g., to allow for gasflow through the ceramic article and into a processing chamber). Theapertures may have been formed by drilling (e.g., acoustic drilling,laser drilling, mechanical drilling, etc.) into the ceramic article. Theapertures may additionally be reamed following the drilling to increasea diameter of the drilled aperture.

To increase the smoothness of the interior surfaces of the apertures, anabrasive media is introduced into the apertures using an abrasive flowsystem. Abrasive flow machining is a surface finishing process thatinvolves the flowing of a highly viscous abrasive media throughapertures, slots, or other areas which may be difficult to reach byconventional polishing technologies. The abrasive media includes ahighly viscous polymer base and abrasive particles such as siliconcarbide, diamond, and/or boron nitride particles. The polishing effectcan be varied by adjusting the viscosity of the media (e.g., changingthe type of the polymer component or the amount of the abrasive loadinginto the polymer), a grit and/or type of the abrasive particles, and/ora pressure used to flow the media inside the apertures.

The disclosed systems and methods provide improved (e.g., smoother)surface finish within small apertures of semiconductor chamber ceramicarticles over traditional articles. The improved surface finish of theapertures advantageously facilitates processing of semiconductor wafersby reducing particulates that result from use of the ceramic articlewithin the semiconductor processing chamber. The systems and methodsdescribed herein further advantageously reduce process operations (e.g.,oxidation and/or radio frequency conditioning) and/or processing timesfor the fabrication of chamber components used in process gasdistribution. Radio frequency (RF) conditioning is the process ofperforming one or more operations to season or condition a chambercomponent. Moreover, some embodiments of the disclosed methods utilizedrilling followed by reaming to produce apertures. When drilling andreaming is performed in conjunction with abrasive flow polishing,defects produced in the drilling/reaming process can be mitigated.Mitigation of the defects allows for robust and novel ways offabricating apertures in ceramic articles.

FIG. 1 is a sectional view of a semiconductor processing chamber 100.The processing chamber 100 may be used for processes in which acorrosive plasma environment is provided. For example, the processingchamber 100 may be a chamber for a plasma etcher or plasma etch reactor,a plasma cleaner, and so forth. Examples of chamber components that mayinclude one or more apertures include, but are not limited to, asubstrate support assembly 148, an electrostatic chuck (ESC) 150, a gasdistribution plate, a nozzle, a showerhead, a flow equalizer, a coolingbase, a gas feeder, and a chamber lid 104. The apertures, which aredescribed in greater detail below, may be apertures formed by drillingand/or reaming the chamber component during fabrication. The chambercomponent may be a ceramic article having a compositing of at least oneof Al₂O₃, AlN, SiO₂, Y₃Al₅O₁₂, Y₄Al O₁₂, Y₄Al₂O₉, Er₂O₃, Gd₂O₃,Gd₃Al₅O₁₂, YF₃, Nd₂O₃, Er₄Al₂O₉, Er₃Al₅O₁₂, ErAlO₃, Gd₄Al₂O₉, GdAlO₃,Nd₃Al₅O₁₂, Nd₄Al₂O₉, NdAlO₃, or a ceramic compound composed of Y₄Al₂O₉and a solid-solution of Y₂O₃-ZrO₂.

In one embodiment, the processing chamber 100 includes a chamber body102 and a showerhead 130 that enclose an interior volume 106.Alternatively, the showerhead 130 may be replaced by a lid and a nozzlein some embodiments. The chamber body 102 may be fabricated fromaluminum, stainless steel or other suitable material. The chamber body102 generally includes sidewalls 108 and a bottom 110. One or more ofthe showerhead 130 (or lid and/or nozzle), sidewalls 108 and/or bottom110 may include a one or more apertures.

An outer liner 116 may be disposed adjacent the sidewalls 108 to protectthe chamber body 102. The outer liner 116 may be fabricated to includeone or more apertures. In one embodiment, the outer liner 116 isfabricated from aluminum oxide.

An exhaust port 126 may be defined in the chamber body 102, and maycouple the interior volume 106 to a pump system 128. The pump system 128may include one or more pumps and throttle valves utilized to evacuateand regulate the pressure of the interior volume 106 of the processingchamber 100.

The showerhead 130 may be supported on the sidewall 108 of the chamberbody 102. The showerhead 130 (or lid) may be opened to allow access tothe interior volume 106 of the processing chamber 100, and may provide aseal for the processing chamber 100 while closed. A gas panel 158 may becoupled to the processing chamber 100 to provide process and/or cleaninggases to the interior volume 106 through the showerhead 130 or lid andnozzle (e.g., through apertures of the showerhead or lid and nozzle).Showerhead 130 may be used for processing chambers used for dielectricetch (etching of dielectric materials). The showerhead 130 includes agas distribution plate (GDP) 133 having multiple gas delivery apertures132 throughout the GDP 133. The showerhead 130 may include the GDP 133bonded to an aluminum base or an anodized aluminum base. The GDP 133 maybe made from Si or SiC, or may be a ceramic such as Y₂O₃, Al₂O₃, YAG,and so forth.

For processing chambers used for conductor etch (etching of conductivematerials), a lid may be used rather than a showerhead. The lid mayinclude a center nozzle that fits into a center hole of the lid. The lidmay be a ceramic such as Al₂O₃, Y₂O₃, YAG, or a ceramic compoundcomposed of Y₄Al₂O₉ and a solid-solution of Y₂O₃-ZrO₂. The nozzle mayalso be a ceramic, such as Y₂O₃, YAG, or the ceramic compound composedof Y₄Al₂O₉ and a solid-solution of Y₂O₃-ZrO₂. The lid, base ofshowerhead 130, GDP 133 and/or nozzle may be coated with a ceramiclayer, which may be composed of one or more of any of the ceramiccompositions described herein. The ceramic layer may be a plasma sprayedlayer, a physical vapor deposition (PVD) deposited layer, an ionassisted deposition (IAD) deposited layer, or other type of layer. Inone embodiment, the ceramic layer may have been coated onto the chambercomponent prior to formation of apertures.

Examples of processing gases that may be used to process substrates inthe processing chamber 100 include halogen-containing gases, such asC₂F₆, SF₆, SiCl₄, HBr, NF₃, CF₄, CHF₃, CH₂F₃, F, NF₃, Cl₂, CCl₄, BCl₃and SiF₄, among others, and other gases such as O₂, or N₂O. Examples ofcarrier gases include N₂, He, Ar, and other gases inert to process gases(e.g., non-reactive gases). The substrate support assembly 148 isdisposed in the interior volume 106 of the processing chamber 100 belowthe showerhead 130 or lid. The substrate support assembly 148 holds thesubstrate 144 during processing. A ring 146 (e.g., a single ring) maycover a portion of the electrostatic chuck 150, and may protect thecovered portion from exposure to plasma during processing. The ring 146may be silicon or quartz in one embodiment.

An inner liner 118 may be coated on the periphery of the substratesupport assembly 148. The inner liner 118 may be a halogen-containinggas resistant material such as those discussed with reference to theouter liner 116. In one embodiment, the inner liner 118 may befabricated from the same materials of the outer liner 116. Additionally,the inner liner 118 may be coated with a ceramic layer and/or have oneor more apertures passing through.

In one embodiment, the substrate support assembly 148 includes amounting plate 162 supporting a pedestal 152, and an electrostatic chuck150. The electrostatic chuck 150 further includes a thermally conductivebase 164 and an electrostatic puck 166 bonded to the thermallyconductive base by a bond 138, which may be a silicone bond in oneembodiment. An upper surface of the electrostatic puck 166 is covered bythe ceramic layer 136 in the illustrated embodiment. In one embodiment,the ceramic layer 136 is disposed on the upper surface of theelectrostatic puck 166. In another embodiment, the ceramic layer 136 isdisposed on the entire exposed surface of the electrostatic chuck 150including the outer and side periphery of the thermally conductive base164 and the electrostatic puck 166. The mounting plate 162 is coupled tothe bottom 110 of the chamber body 102 and includes passages for routingutilities (e.g., fluids, power lines, sensor leads, etc.) to thethermally conductive base 164 and the electrostatic puck 166.

The thermally conductive base 164 and/or electrostatic puck 166 mayinclude one or more optional embedded heating elements 176, embeddedthermal isolators 174 and/or conduits 168, 170 to control a lateraltemperature profile of the substrate support assembly 148. The conduits168, 170 may be fluidly coupled to a fluid source 172 that circulates atemperature regulating fluid through the conduits 168, 170. The embeddedthermal isolator 174 may be disposed between the conduits 168, 170 inone embodiment. The heating element 176 is regulated by a heater powersource 178. The conduits 168, 170 and heating element 176 may beutilized to control the temperature of the thermally conductive base164, which may be used for heating and/or cooling the electrostatic puck166 and a substrate 144 (e.g., a wafer) being processed. The temperatureof the electrostatic puck 166 and the thermally conductive base 164 maybe monitored using a plurality of temperature sensors 190, 192, whichmay be monitored using a controller 195.

The electrostatic puck 166 may further include multiple gas passages orapertures such as grooves, mesas and other surface features, which maybe formed in an upper surface of the electrostatic puck 166 and/or theceramic layer 136. The gas passages may be polished in accordance withembodiments described herein. The gas passages may be fluidly coupled toa source of a heat transfer (or backside) gas such as helium viaapertures drilled in the electrostatic puck 166. In operation, thebackside gas may be provided at controlled pressure into the gaspassages to enhance the heat transfer between the electrostatic puck 166and the substrate 144. The electrostatic puck 166 includes at least oneclamping electrode 180 controlled by a chucking power source 182. Theclamping electrode 180 (or other electrode disposed in the electrostaticpuck 166 or conductive base 164) may further be coupled to one or moreRF power sources 184, 186 through a matching circuit 188 for maintaininga plasma formed from process and/or other gases within the processingchamber 100. The power sources 184, 186 are generally capable ofproducing an RF signal having a frequency from about 50 kHz to about 3GHz, with a power output of up to about 10,000 Watts.

FIG. 2 illustrates an exemplary architecture of a manufacturing system200 according to one embodiment. The manufacturing system 200 may be aceramics manufacturing system, which may include the processing chamber100. In some embodiments, the manufacturing system 200 may be aprocessing chamber for manufacturing, cleaning, or modifying a chambercomponent of the processing chamber 100. In one embodiment, themanufacturing system 200 includes an abrasive flow system 205, anequipment automation layer 215, and a computing device 220. Inalternative embodiments, the manufacturing system 200 may include moreor fewer components. For example, the manufacturing system 200 mayinclude only the abrasive flow system 205, which may be a manualoff-line machine.

The abrasive flow system 205 may be a machine designed to direct a flowof an abrasive media through one or more apertures of an article (e.g.,a ceramic article for use in a semiconductor processing chamber). Theabrasive flow system 205 may include a mounting stage and a clamp usedto hold the article in place during processing, so as to produce afixture with a sealed flow path for flowing the abrasive media throughthe article. The abrasive flow system 205 may include an external pumpfor pumping the abrasive media through the fixture. The clamp may be apneumatic or hydraulic clamp, and the abrasive flow system 205 mayadditionally include other pumps that are used to generate a clampingforce.

The abrasive flow system 205 may be an off-line machine that can beprogrammed with a process recipe. The process recipe may control theapplied clamping force, flow rates, flow directions, process times, orany other suitable parameter. Alternatively, abrasive flow system 205may be an on-line automated machine that can receive process recipesfrom computing devices 220 (e.g., personal computers, server machines,etc.) via an equipment automation layer 215. The equipment automationlayer 215 may interconnect the abrasive flow system 205 with computingdevices 220, with other manufacturing machines, with metrology tools,and/or other devices.

The equipment automation layer 215 may include a network (e.g., alocation area network (LAN)), routers, gateways, servers, data stores,and so on. The abrasive flow system 205 may connect to the equipmentautomation layer 215 via a SEMI Equipment CommunicationsStandard/Generic Equipment Model (SECS/GEM) interface, via an Ethernetinterface, and/or via other interfaces. In one embodiment, the equipmentautomation layer 215 enables process data (e.g., data collected by theabrasive flow system 205 during a process run) to be stored in a datastore (not shown). In an alternative embodiment, the computing device220 connects directly to the abrasive flow system 205.

In one embodiment, the abrasive flow system 205 includes a programmablecontroller that can load, store and execute process protocols. Theprogrammable controller may pressure settings, fluid flow settings, timesettings, etc. for a process performed by abrasive flow system 205. Theprogrammable controller may include a main memory (e.g., read-onlymemory (ROM), flash memory, dynamic random access memory (DRAM), staticrandom access memory (SRAM), etc.), and/or a secondary memory (e.g., adata storage device such as a disk drive). The main memory and/orsecondary memory may store instructions for performing abrasive flowpolishing, as described herein.

The programmable controller may also include a processing device coupledto the main memory and/or secondary memory (e.g., via a bus) to executethe instructions. The processing device may be a general-purposeprocessing device such as a microprocessor, central processing unit, orthe like. The processing device may also be a special-purpose processingdevice, such as an application specific integrated circuit (ASIC), afield programmable gate array (FPGA), a digital signal processor (DSP),a network processor, or the like. In one embodiment, programmablecontroller is a programmable logic controller (PLC).

FIG. 3 depicts a sectional view of an abrasive flow system 300 accordingto an embodiment. For example, the abrasive flow system 300 may be thesame or similar to manufacturing system 200 described with respect toFIG. 2. The abrasive flow system 300 may be configured to performabrasive flow polishing on an article 302 (e.g., a ceramic chambercomponent). A fixture may be formed by clamping the article 302 betweena clamp 318 and a mounting stage 314. A ring 322 may be placed aroundthe article 302, which contacts the mounting stage 314 and the clamp318. Each of the mounting stage 314, the clamp 318, and the ring 322 maybe a metallic material (e.g., stainless steel) or a ceramic material(e.g., any of the ceramic compositions described herein). In someembodiments, o-rings are placed between the mounting stage 314 and thering 322 and/or the clamp 318 and the ring 322. In some embodiments, theclaim 318 may be a hydraulic clamp or a pneumatic clamp. The clamp 318may be capable of applying a clamping pressure between about 1500 poundsper square-inch (psi) and about 2500 psi to the article 302.

The article 302 may be any suitable chamber component described withrespect to FIG. 1, including a substrate support assembly, anelectrostatic chuck (ESC), a chamber wall, a base, a gas distributionplate or showerhead, a liner, a liner kit, a shield, a plasma screen, aflow equalizer, a cooling base, a chamber lid, etc. The article 302 maybe a ceramic material, metal-ceramic composite, or a polymer-ceramiccomposite. As illustrated in FIG. 3, the article 302 includes apertures304 and 310, which pass through the article 302. The apertures 304 and310 may have any suitable shape, such as circular, c-slot, etc. Othershapes of the apertures 304 and 310 may also be provided. The article302 may have any suitable dimensions for incorporation into asemiconductor chamber. For example, in some embodiments, the article 302may be a showerhead having a thickness between about 50 mm to about 200mm. The article 302 may also have a diameter of between about 200 toabout 500 mm.

As depicted in FIG. 3, in one embodiment the aperture 304 includes afirst region 306 a having a first diameter (e.g., about 0.1 inches) anda second region 306 b having a second diameter (e.g., about 0.05inches). The aperture 304 is formed by the first region 306 a and secondregion 306 b joined by a junction 308 between the first region 306 a andsecond region 306 b. For example, the first region 306 may have beenformed by drilling a hole into the article 302 using a first drill, andthe second region 306 b may have been formed by drilling a hole into thearticle 302 using a second drill with a smaller diameter bit than thefirst drill. Aperture 310 may have been formed in a similar manner asaperture 304. For example, aperture 310 has a first region 312 a havinga first diameter and a second region 312 b having a second diameter. Insome embodiments, for any aperture, a diameter of the aperture may rangefrom about 0.01 inches to about 0.1 inches. It is noted that apertures304 and 310 are merely illustrative, and any suitable aperture (e.g.,with or without bends and with or without multiple diameters) may beformed in article 302.

The mounting stage 314 may include multiple apertures passing throughthe mounting stage 314, such as central aperture 316 a and sideapertures 316 b. Similarly, the clamp 318 may include multiple aperturespassing through the clamp 318, such as central aperture 320 a and sideapertures 320 b. The mounting stage 314, clamp 318, and their respectiveapertures 316 a, 316 b, 320 a, and 320 b may be sized and shaped tointerface with the article 302 such that flow paths 332 and 334 aredefined through the mounting stage 314, article 302, and clamp 318 foran abrasive media to pass through. In some embodiments, one or more ofpads 324 and 326 may be placed, respectively, between the clamp 318 andthe article 302 and between the mounting stage 314 and the article 302.Each of pads 324 and 326 may be multilayered and/or have multiple pads.In some embodiments, the pads 324 and 326 are rubber pads (e.g.,urethane, polyoxymethylene, etc.). The pads 324 and 326 may befabricated to be of suitable shapes to allow for variance in theheight/dimensions of the article 302. In some embodiments, if less thanall of the apertures of the article are to be polished with the abrasivemedia, one or more of the mounting stage 314, the pads 324 and 326, theclamp 318, and the ring 322 may be fabricated/machined such that theflow path passes through the apertures that are to be polished whileblocking the flowpath through the one or more apertures that are not tobe polished.

A pump 330 may be coupled to the mounting stage 314 and the clamp 318.The pump 330 may provide the pressure used to flow the abrasive mediathrough the apertures 304 and 310 of the article 302. For example, thepump 330 may be an axial piston pump, a radial piston pump, a hydraulicpump, etc. In one embodiment, the pressure applied by the pump 330 isbetween about 500 psi and about 1500 psi. The pump 330 may be configuredto repeatedly flow the abrasive media back and forth through theapertures 304 and 310 for a duration of time suitable for producing asmooth finish within the aperture interiors. Accordingly, the pump 330may flow the abrasive media through the apertures 304, 310 in a firstdirection, and then reverse the flow of the abrasive media and flow itback through the apertures 304, 310 in the opposite direction. In oneembodiment, the pump may include a piston disposed on either side of thefixture (e.g., on either side of the mounting stage 314 and the clamp318). The abrasive media may be forced through the apertures 316 a, 316b, 304, 310, 320 a, and 320 b by alternating the stroke of each piston.The force supplied by each piston, the frequency of the piston motion,and the total processing time may be adjusted to polish the interiorsurfaces of the apertures 304 and 310. In some embodiments, theprocessing time duration is between about 5 minutes and about 30minutes.

The processing time duration may be pre-determined based on previouslygenerated surface morphology micrographs used as guidelines fordetermining a target finish. In one embodiment, the target finish timeis based on a measured surface roughness. For example, a protocol (e.g.,including parameters such as abrasive grit, abrasive particleconcentration, number of cycles, pressures, etc.) may be defined bydetermining a combination of parameters that yield a particular range ofsurface roughnesses. In one embodiment, the processing time duration maybe selected such that a target volume of abrasive media is flowedthrough the apertures. Given a flow rate Q (which can be controlled bythe pump 330) and a target volume V, the total processing time t isdefined as V/Q. In some implementations, a flow rate is between about 10in³/min and about 30 in³/min, and a total processing time is betweenabout 10 minutes and about 30 minutes.

In some embodiments, the abrasive media may be a slurry. For example,the slurry may include abrasive particles dispersed in a liquid, such asa high viscosity liquid having a polymer base. The particles may bedelivered to the interior of apertures of a ceramic article in asolution containing water, an oil-based plasticizer, and/or any otherliquid capable of suspending the particles. In some embodiments, theparticles may make up between about 10 to about 80 percent by weight ofthe slurry. The viscosity of the slurry may be adjusted by adjustingeither particle concentration, solution composition, or a combinationthereof. Increased viscosity may result in greater smoothness of theinterior surfaces of the apertures and improved removal of the damagedsurfaces. In some embodiments, the viscosity of the slurry may bebetween about 150,000 centiPoise (cP) to about 750,000 cP. In someembodiments, the particles may comprise at least one of diamond, siliconcarbide (SiC), or boron carbide (BC). In some embodiments, amass-median-diameter (D50) of the particles in the slurry, which is theaverage particle diameter by mass, may be between about 1 micrometer andabout 100 micrometers. In some embodiments, a D50 of the particles maybe between about 20 micrometers and about 30 micrometers. Smaller gritsizes may cause the polished surface of the apertures to be smoother.However, in some instances it takes longer to polish the apertures withsmaller grit sizes. In some instances, a first abrasive media with afirst grit size is used initially followed by a second abrasive mediahaving a second smaller grit size.

FIGS. 4a-4i are micrographs comparing unpolished apertures to aperturespolished according to an embodiment. Each of FIGS. 4a-4i show theinterior surfaces of a 0.05 inch diameter aperture within a chambernozzle. FIGS. 4a-c show different views of the aperture of the nozzleprior to abrasive flow polishing, in which cracks and grain boundariesalong the interior surface are clearly visible. FIGS. 4d-f show aninterior surface of an aperture after abrasive flow polishing with 250in³ of abrasive media. FIGS. 4g-i show the interior surface of anaperture after abrasive flow polishing with 500 in³ of abrasive media,showing an improvement over FIGS. 4d-f with increasing abrasive mediatreatment (a surface roughness less than 25 μin)

FIG. 5 is a flow diagram illustrating a process 500 for polishinginterior surfaces of apertures in an article according to an embodiment.At block 502, an article is provided, the article having at least oneaperture and being a component for a semiconductor processing chamber.In one embodiment, one or more apertures of the article vary indiameter. For example, a first portion of the aperture may have a firstdiameter and a second portion of the aperture may have a seconddiameter. The one or more apertures may also be non-linear (e.g., theaperture may change directions within the article). An aperture withmultiple diameters and that changes directions poses challenges toconventional polishing techniques.

In one embodiment, the article is a semiconductor chamber component,such as a lid, a nozzle, an electrostatic chuck, a showerhead, a linerkit, or any other suitable chamber component having apertures. In oneembodiment, the article is a metal article such as aluminum, an aluminumalloy, titanium, stainless steel, and so on. In one embodiment, thearticle is a polymer based material. In one embodiment, the articleincludes multiple different materials (e.g., a metal base and a ceramiclayer over the metal base).

In one embodiment, the article is a ceramic article. In one embodiment,the article may be a ceramic article having a composition that includesone or more of Al₂O₃, AlN, SiO₂, Y₃Al₅O₁₂, Y₄Al₂O₉, Y₂O₃, Er₂O₃, Gd₂O₃,Er₃Al₅O₁₂, Gd₃Al₅O₁₂, YF₃, Nd₂O₃, Er₄Al₂O₉, ErAlO₃, Gd₄Al₂O₉, GdAlO₃,Nd₃Al₅O₁₂, Nd₄Al₂O₉, NdAlO₃, or a ceramic compound composed of Y₄Al₂O₉and a solid-solution of Y₂O₃-ZrO₂. In some embodiments, the article mayalternatively or additionally include ZrO₂, Al₂O₃, SiO₂, B₂O₃, Nd₂O₃,Nb₂O₅, CeO₂, Sm₂O₃, Yb₂O₃, or other oxides.

With reference to the ceramic compound composed of Y₄Al₂O₉ and asolid-solution of Y₂O₃-ZrO₂, in one embodiment, the ceramic compoundincludes 62.93 molar ratio (mol %) Y₂O₃, 23.23 mol % ZrO₂ and 13.94 mol% Al₂O₃. In another embodiment, the ceramic compound can include Y₂O₃ ina range of 50-75 mol %, ZrO₂ in a range of 10-30 mol % and Al₂O₃ in arange of 10-30 mol %. In another embodiment, the ceramic compound caninclude Y₂O₃ in a range of 40-100 mol %, ZrO₂ in a range of 0-60 mol %and Al₂O₃ in a range of 0-10 mol %. In another embodiment, the ceramiccompound can include Y₂O₃ in a range of 40-60 mol %, ZrO₂ in a range of30-50 mol % and Al₂O₃ in a range of 10-20 mol %. In another embodiment,the ceramic compound can include Y₂O₃ in a range of 40-50 mol %, ZrO₂ ina range of 20-40 mol % and Al₂O₃ in a range of 20-40 mol %. In anotherembodiment, the ceramic compound can include Y₂O₃ in a range of 70-90mol %, ZrO₂ in a range of 0-20 mol % and Al₂O₃ in a range of 10-20 mol%. In another embodiment, the ceramic compound can include Y₂O₃ in arange of 60-80 mol %, ZrO₂ in a range of 0-10 mol % and Al₂O₃ in a rangeof 20-40 mol %. In another embodiment, the ceramic compound can includeY₂O₃ in a range of 40-60 mol %, ZrO₂ in a range of 0-20 mol % and Al₂O₃in a range of 30-40 mol %. In another embodiment, the ceramic compoundcan include Y₂O₃ in a range of 30-60 mol %, ZrO₂ in a range of 0-20 mol% and Al₂O₃ in a range of 30-60 mol %. In another embodiment, theceramic compound can include Y₂O₃ in a range of 20-40 mol %, ZrO₂ in arange of 20-80 mol % and Al₂O₃ in a range of 0-60 mol %. In otherembodiments, other distributions may also be used for the ceramiccompound.

In one embodiment, an alternative ceramic compound that includes acombination of Y₂O₃, ZrO₂, Er₂O₃, Gd₂O₃ and SiO₂ is used for thearticle. In one embodiment, the alternative ceramic compound can includeY₂O₃ in a range of 40-45 mol %, ZrO₂ in a range of 0-10 mol %, Er₂O₃ ina range of 35-40 mol %, Gd₂O₃ in a range of 5-10 mol % and SiO2 in arange of 5-15 mol %. In another embodiment, the alternative ceramiccompound can include Y₂O₃ in a range of 30-60 mol %, ZrO₂ in a range of0-20 mol %, Er₂O₃ in a range of 20-50 mol %, Gd₂O₃ in a range of 0-10mol % and SiO2 in a range of 0-30 mol %. In a first example, thealternative ceramic compound includes 40 mol % Y₂O₃, 5 mol % ZrO₂, 35mol % Er₂O₃, 5 mol % Gd₂O₃ and 15 mol % SiO₂. In a second example, thealternative ceramic compound includes 45 mol % Y₂O₃, 5 mol % ZrO₂, 35mol % Er₂O₃, 10 mol % Gd₂O₃ and 5 mol % SiO₂. In a third example, thealternative ceramic compound includes 40 mol % Y₂O₃, 5 mol % ZrO₂, 40mol % Er₂O₃, 7 mol % Gd₂O₃ and 8 mol % SiO₂. In one embodiment, thearticle includes 70-75 mol % Y₂O₃ and 25-30 mol % ZrO₂. In a furtherembodiment, the article is a material entitled YZ20 that includes 73.13mol % Y₂O₃ and 26.87 mol % ZrO₂.

Referring back to FIG. 5, at block 504, the at least one aperture of thearticle is polished based on flowing an abrasive media through the atleast one aperture of the article. The abrasive media includes a polymerbase and multiple abrasive particles suspended in the polymer base. Theabrasive media may polish the apertures even if the apertures vary indiameter and are non-linear. In one embodiment, the abrasive particlesinclude at least one of silicon carbide, diamond, or boron nitride. Anaverage size of the abrasive particles may range from 5 micrometers to100 micrometers. In one embodiment, the article is polished using anabrasive flow system (e.g., abrasive flow system 300), which isdescribed in more detail below with respect to FIG. 6.

FIG. 6 is a flow diagram illustrating a process 600 for polishinginterior surfaces of apertures in a ceramic article according to anotherembodiment. At block 602, a ceramic article is provided. The ceramicarticle may by any suitable ceramic article described herein, such as acomponent of a semiconductor processing chamber. The ceramic article mayinclude one or more of the ceramic materials described with respect toblock 502 of FIG. 5.

At block 604, holes are drilled through the ceramic article to produceat least one aperture. In one embodiment, each aperture may be of a sizerange from about 0.01 inches to about 0.1 inches. In one embodiment, afirst hole having a first diameter (e.g., between about 0.05 inches and0.1 inches) is drilled into or through the ceramic article, and a secondhole having a second diameter (e.g., between about 0.01 inches and about0.05 inches) is drilled into the ceramic article (e.g., through thefirst hole, or into a different portion of the ceramic article). Thefirst and second holes may intersect, forming an aperture through theceramic article that has a first diameter at a first region(corresponding to the first hole) and a second diameter at a secondregion (corresponding to the second hole). In one embodiment, the firstdiameter is greater than the second diameter. In one embodiment, thefirst region is parallel with the second region (e.g., a linear aperturehaving two different diameters at different portions). In oneembodiment, the aperture has a bend (e.g, the first region and secondregion intersect, but are not parallel).

In one embodiment, at block 606, the at least one aperture is reamedwith a reaming device to increase a diameter of the at least oneaperture. The diameter of the reaming device may be selected to belarger than a diameter of the at least one aperture (e.g., by about 0.5%to about 2% larger that the diameter of the at least one aperture). Inone embodiment, the drill may have a first grit size, and the ream mayhave a second grit size, and the first grit size of the drill is courserthan the second grit size of the ream. In one embodiment, the first gritsize of the drill is between about 100 grit and about 150 grit. In oneembodiment, the second grit size of the reaming device is between about400 grit (e.g., about 40 micrometer particle size) and 800 grit (e.g.,about 25 micrometer particle size).

At block 608, the ceramic article is clamped within an abrasive flowsystem (e.g., abrasive flow system 300 of FIG. 3). The abrasive flowsystem may include a mounting stage (e.g., mounting stage 314) and aclamp (e.g., clamp 318). The ceramic article may be placed between theclamp and the mounting stage such that a flow path for an abrasive mediais defined by the at least one aperture, such that the abrasive mediamay flow from the mounting stage, through the at least one aperture, andthrough the clamp (as illustrated in FIG. 3). In some embodiments, theclamp may be a hydraulic clamp or a pneumatic clamp. In someembodiments, the clamp may apply a clamping pressure to the ceramicarticle that is between about 1,500 psi and 2,500 psi. In someembodiments, one or more pads (e.g., pads 326 and 324) are disposedbetween the ceramic article and the clamp, and/or the ceramic articleand the mounting stage.

At block 610, the at least one aperture is polished by pumping theabrasive media through the at least one aperture using the abrasive flowsystem. A pump (e.g., pump 330) may be fluidly coupled to the abrasiveflow system such that the abrasive media flows through the at least oneaperture of the ceramic article. In one embodiment, the pump provides apressure of about 500 psi to about 1000 psi to the abrasive media. Inone embodiment, the abrasive media includes many abrasive particles(e.g., thousands or tens of thousands of abrasive particles). Theabrasive particles may include at least one or silicon carbide, diamond,or boron nitride particles. In one embodiment, the average size of eachof the plurality of abrasive particles ranges from 5 to 100 micrometers.

At block 612, a flow direction of the abrasive media through the atleast one aperture is periodically adjusted over a time duration. In oneembodiment, the time duration is between about 20 minutes and about 60minutes. In one embodiment, the flow direction may be changed (e.g.,from a forward direction to a reverse direction) one or more timesduring the time duration. For example, the flow direction may be changedevery 5-10 minutes. In one embodiment, the abrasive media includes anoil-based plasticizer. In one embodiment, a viscosity of the abrasivemedia is between about 150,000 cP and about 750,000 cP.

After flowing the abrasive media through the at least one aperture, theat least one aperture may have a surface roughness (average surfaceroughness, Ra) of less than 32 μin. In one embodiment, an opening of theat least one aperture (at an outer surface of the ceramic article) has arounded edge after the polishing.

In one embodiment, a ceramic plasma resistant layer is formed on thearticle after the apertures are polished. The ceramic plasma resistantlayer may be composed of any of the aforementioned ceramics, and may bedeposited onto the article by plasma spraying, physical vapordeposition, ion assisted deposition, or other deposition techniques. Inan alternative embodiment, the ceramic plasma resistant layer may beformed on a surface of the article before the holes are drilled and thepolishing is performed.

The preceding description sets forth numerous specific details such asexamples of specific systems, components, methods, and so forth, inorder to provide a good understanding of several embodiments of thepresent invention. It will be apparent to one skilled in the art,however, that at least some embodiments of the present invention may bepracticed without these specific details. In other instances, well-knowncomponents or methods are not described in detail or are presented insimple block diagram format in order to avoid unnecessarily obscuringthe present invention. Thus, the specific details set forth are merelyexemplary. Particular embodiments may vary from these exemplary detailsand still be contemplated to be within the scope of the presentdisclosure.

Reference throughout this specification to “one embodiment” or “anembodiment” indicates that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. Thus, the appearances of the phrase “in oneembodiment” or “in an embodiment” in various places throughout thisspecification are not necessarily all referring to the same embodiment.In addition, the term “or” is intended to mean an inclusive “or” ratherthan an exclusive “or.” When the term “about” or “approximately” is usedherein, this is intended to mean that the nominal value presented isprecise within ±10%.

Although the operations of the methods herein are shown and described ina particular order, the order of the operations of each method may bealtered so that certain operations may be performed in an inverse orderor so that certain operation may be performed, at least in part,concurrently with other operations. In another embodiment, instructionsor sub-operations of distinct operations may be in an intermittentand/or alternating manner.

It is to be understood that the above description is intended to beillustrative, and not restrictive. Many other embodiments will beapparent to those of skill in the art upon reading and understanding theabove description. The scope of embodiments of the invention should,therefore, be determined with reference to the appended claims, alongwith the full scope of equivalents to which such claims are entitled.

What is claimed is:
 1. A chamber component, comprising: a ceramic body;and a plurality of polished apertures in the ceramic body, wherein aroughness of the plurality of polished apertures is less than 32 μin,wherein the ceramic body comprises a compound that includes acombination of Y₂O₃, ZrO₂, Er₂O₃, Gd₂O₃, and SiO₂, and wherein the atleast one aperture of the plurality of apertures is polished by flowingan abrasive media through the at least one aperture, wherein theabrasive media comprises a polymer base and a plurality of abrasiveparticles, and wherein a viscosity of the abrasive media is betweenabout 150,000 cP and about 750,000 cP.
 2. The chamber component of claim1, wherein at least one of the plurality of polished apertures has afirst diameter at a first region and a second diameter at a secondregion, wherein the second diameter is less than the first diameter. 3.The chamber component of claim 1, wherein at least one of the pluralityof polished apertures comprises at least one bend within the chambercomponent.
 4. The chamber component of claim 1, wherein an opening of atleast one of the plurality of apertures has a rounded edge.
 5. Thechamber component of claim 1, wherein the chamber component is ashowerhead gas distribution plate or a nozzle.
 6. The chamber componentof claim 1, wherein a diameter of the at least aperture of the pluralityof apertures is between about 0.01 inches and about 0.1 inches.
 7. Thechamber component of claim 1, wherein flowing the abrasive media throughthe at least one aperture comprises periodically adjusting a flowdirection of the abrasive media through the at least one aperture over atime duration, wherein a length of the time duration is between about 20minutes and about 60 minutes.
 8. The chamber component of claim 1,wherein the plurality of abrasive particles comprises at least one ofsilicon carbide, diamond, or boron nitride.
 9. The chamber component ofclaim 1, wherein an average size of each of the plurality of abrasiveparticles is between 5 micrometers and 100 micrometers.
 10. The chambercomponent of claim 1, wherein the abrasive media further comprises anoil-based plasticizer.
 11. The chamber component of claim 1, wherein atleast one aperture of the plurality of apertures is formed by: drillingwith a drill through the ceramic article to produce the at least oneaperture; and reaming with a reaming device the at least one aperturewith a reaming device to increase a diameter of the at least oneaperture prior to performing the polishing.
 12. The chamber component ofclaim 11, wherein a first grit size of the drill is courser than asecond grit size of the reaming device, wherein the first grit size ofthe drill is between about 100 grit and about 150 grit, and wherein thesecond grit size of the reaming device is between about 400 grit andabout 800 grit.
 13. The chamber component of claim 1, wherein thechamber component is a plasma-resistant component of a semiconductorprocessing chamber that generates a plasma environment.
 14. The chambercomponent of claim 1, wherein the chamber component is selected from agroup consisting of a substrate support assembly, an electrostaticchuck, a gas distribution plate, a nozzle, a showerhead, a flowequalizer, a cooling base, a gas feeder, a liner kit, and a chamber lid.15. A semiconductor processing chamber comprising: a plasma-resistantchamber component having a ceramic body and a plurality of polishedapertures in the ceramic body, wherein a roughness of the plurality ofpolished apertures is less than 32 μin, wherein the ceramic bodycomprises one of Y₂O₃, Y₄Al₂O₉, or a compound that includes acombination of Y₄Al₂O₉ and a solid-solution of Y₂O₃-ZrO₂, and whereinthe at least one aperture of the plurality of apertures is polished byflowing an abrasive media through the at least one aperture, wherein theabrasive media comprises a polymer base and a plurality of abrasiveparticles, and wherein a viscosity of the abrasive media is betweenabout 150,000 cP and about 750,000 cP.
 16. The semiconductor processingchamber of claim 15, wherein the chamber component is selected from agroup consisting of a substrate support assembly, an electrostaticchuck, a gas distribution plate, a nozzle, a showerhead, a flowequalizer, a cooling base, a gas feeder, a liner kit, and a chamber lid.17. A semiconductor processing chamber comprising: a plasma-resistantchamber component having a ceramic body and a plurality of polishedapertures in the ceramic body, wherein a roughness of the plurality ofpolished apertures is less than 32 μin, and wherein the ceramic bodycomprises a compound that includes at least one of Nd₃Al₅O₁₂, Nd₄Al₂O₉,or NdAlO₃, and wherein the at least one aperture of the plurality ofapertures is polished by flowing an abrasive media through the at leastone aperture, wherein the abrasive media comprises a polymer base and aplurality of abrasive particles, and wherein a viscosity of the abrasivemedia is between about 150,000 cP and about 750,000 cP.
 18. Thesemiconductor processing chamber of claim 17, wherein the chambercomponent is selected from a group consisting of a substrate supportassembly, an electrostatic chuck, a gas distribution plate, a nozzle, ashowerhead, a flow equalizer, a cooling base, a gas feeder, a liner kit,and a chamber lid.